Weddings and RAW Files for Clients

I haven't shot weddings and I'm only a semi-pro, but I've been interviewing potential photographers for my personal wedding. All tell me they shoot RAW and provide jpegs. When I ask if they can provide the RAW along with the jpeg I have received quite a mixed reaction from "no problem" to "Why are you asking for that, don't you like my work!" to " I charge extra for that," to "No." One of the photographers my fiance and I really like only shoots 10 MP RAW from his 5dII so I don't see why storage space is even an excuse.

So, my questions to other photographers out there are:

Why would it be so much of a problem to simply include RAW files since the client would also have the polished jpegs.

Should I eliminate a photographer from consideration if s/he doesn't provide RAW files.